Direction maintaining device for dirigible craft



April 26, 1938.

G. RIEPE R DIRECTION MAINTAINING DEVICE FOR DIRIGIBLE CRAFT Filed Aug;15, 1934 2 l 9 4 IN TOR GE/PMQ HEW/5151? ATTORME rs.

Patented Apr. 26, 1938 DIRECTION MAINTAINING DEVICE FOR DIBIGIBLE CRAFTGerhard Rieper, Berlin-Mariendorf, Germany,

assignor to Siemens & Halske, Aktiengesellschaft, Siemensstadt, nearBerlin, Germany, a corporation of Germany Application August 15, 1934;Serial No. 740,007

In G

[10 Claims.

the claims an instrument, whose direction indication or directionfinding effect is not controlled by a radio transmitting station or anyother equipment of the station which is to be reached by the craft, butis based upon general physical properties and .therefore, as for examplea magnet compass, an earth inductor compass, a gyroscopic apparatus, maywell be termed as an absolute one.

Primarily one of the objects of this invention is to combine the saidcourse governing device having an absolute direction indicator withmeans, which will automatically compensate the efiect of drifting,caused by winds having a component parallel to the transverse axis ofthe craft; id est the compensating eifect will be such that the craftwill take the shortest path to the station tobereached. For this purposean operative connection between the absolute direction indicator and aninstrument'measuring directly or indirectly the drift'of the craft isprovided, which connection causes the position of the absolute directionindicator to be automatically influenced by said instrument measuringthe drift in such a way, that the absolute direction indicator will begiven a deflection or deviation compensating such drift.

For the measuringof the drift any well known instruments may be used,but a. very simple arrangement is obtained by using a radio sending andreceiving system, which arrangement naturally requires a radio sendingapparatus at the station to be reached by the craft.

One mode of carrying the invention into effect is illustrated by way ofexample in the accompanying drawing, in' which Fig. 1 shows oneembodiment of the invention,

Figs. 2 to 4 show diagrams serving for better understanding of theoperation of the embodiment shown in Fig. l:

For the purpose of showing'that the absolute direction indicator mayconsist of a combination of a plurality of instruments, in theembodiment illustrated in Fig. 1 a direction indicator composed of agyroscopic and of a magnetic compass is used. But this combineddirection indicator per se is not an object of this invention. The saidarrangement may now be described in the following referring to Fig. 1.

ermany August 16, 1933 The spinning axis l of the gyroscope ishorizontal and the casing 2 of the gyroscope is mounted for oscillationin a vertical ring3 on the horizontal axis 4, the so called interiorCardan axis at right angle to the spinning axis I. With the verticalring 3 in turn is connected a vertical axis 5, the so called exteriorCardan axis, by means of which the vertical ring 3 ismountedforoscillation in stationary bearings 6 about the vertical axis. The massof the gyroscope rotor, the sp'inning'axis of which is l, is soarranged, that its center of gravity coincides with the geometricalpoint of intersection of the two Cardan axes 4 and 5.

The exterior Cardan axis 5 projects with its 5 one end into a casing Ifilled with an electrolytic fluid and carries on the said end anelectrode 8 which is movable within the said casing 1 between twoelectrodes 9 and I0 fixed to the said casing 1. The said threeelectrodes 8, 9 and in are arranged in an electrical circuit whichincludes in the manner shown connecting leads, an alternating currentsource II and electrically parallel to each other a differentialmeasuring instrument i2 on the one hand and a winding 25 carried by thearmature [3 of an electromagnet l4 with a regulating resistor l5 on theother hand. It will be obvious that the measuring instrument indicatesin' a well known manner the deviations of the electrode 8 from itsmiddle position shown in Fig. 1. v

l5 designates a liquid magnetic compass comprising a casing filled withan electrolytic fluid,

a magnetic needle M, an electrode i8 carried by the said needle Ill andmovable within the compass casing between two electrodes l9 and 20 fixedto the casing of the compass IS. The said electrodes l8, l9 and 20 ofthe compass l6 are arranged in an electrical circuit which includesbesides connecting leads, the winding 2| of an electromagnet device 22,the armature 23 of which is connected to thehorizontal Cardan axis 4 ofthe gyroscope casing 2, while the stator 24 of said device 22 is fixedto the vertical ring 3, the circuit also including an alternatingcurrent source 25 and a. regulating resistor 26.

The desired adjustment of the aircraft or other craft is determined byrotating the casing of the compass IS with respect to the parts l1 andI8 and by rotaifing the casing 1 relatively to the sys- 50 the compassl8 and by the casing 1 respectively. The armature ll of theelectromagnet It is mechanically coupled by means of a lever 32 and arod 33 to the on'eend of a doublearmed lever 34, the other end of whichis pivotally connected by means of arod 38 and a lever 38 to a so-calledturn indicator 31. The last mentioned instrument responds to the angularvelocity with which the craft deviates from the predetermined course; itis well known to use such an instrument in connection withautomatimsteering devices for craft for the purpose of preventingoscillations of the craft about a set course. The said lever willaccordingly move in response to the deviation of the craft from the setcourse and to the angular velocity. with which the said deviation takesplace.

lateral rudder 40 of an aircraft or any other craft. The pistons l2 andn and the cylinder ll together constitute an hydraulic servomotor foradjusting the rudder 40.

By means of a conduit 41 the cylinder 44 of the hydraulic servomotor isconnected to a source of operating fluid, illustrated as a pump IIdriven by a motor, for example by an electromotor l9, and which suppliesthe fluid medium from a reservoir ill into the said conduit 41. Thedis-' charged fluid from-the hydraulic motor 42, ll, 44 passes through aconduit II back to the said reservoir II. Passage of operating fluid tothe hydraulic motor is controlled by a piston valve 52 comprisingthreemembers or pistons secured to the valve stem 40 and operating in avalve chamber 53 with which the conduits l1 and Ii communicate as shown.The conduit II is in communication with the two end ports or exhaustports of the valve chamber 53, while the conduit 41 communicates withthe chamber 58 through a port located at about the middle thereof. Thetlfree members of the piston valve 52 are so arranged that in theposition shown they will maintain the three ports closed. on theopposite sides of the central member of the piston valve two ports areprovided in the chamber 53 which are connected by passages 53 and M withthe spaces at the opposite ends of the cylinder 44. ii designates aconduit or by-pass communicating with the conduit 41 and the reser voirSI, and! is a valve in this by-pass, which changed. In the embodimentshown in Fig. 1 the said source of current is in the form of analternator II driven on upon rotational movement of the said handle 21.The alternator i. may be coupled with the handle by means of a gear suchas a worm gear. The predetermined c w s indicated by an indicator 62,which is also coupled to and driven by the handle 21 by means of a wormgear. 59 and til are two springs of small moment each of which is fixedat its one end to the ring 3 and at its other end to a lever 6i carriedby the interior Cardan axis 4. By the action of the said springs 59 andt the axis 4 when deflected will always return into its zero position.

The operation of the elements above described is as follows: Upondeviation of the craft from its course, predetermined by the adjustmentof the casing of the ,magnet compass and of the casing 1 of thegyroscope, the piston valve 52 moves in response to the combined actionof the gyroscope or of the magnet i4, influenced by the gyroscope andthe turn indicator 31. In consequence thereof the pistons 42, 43 of theservomotor will move in a well known manner and adjust the rudder 46. Inthe said manner the craft is maintained on a predetermined course bymeans of the gyroscope. But, as is well known, a free gyroscope in timetends to deviate from its original position. For this reason'themagnetic compass it is provided which will in the manner shown apply acorrective moment about the horizontal axis 4 of the gyroscope by meansof the magnet 22. The said moment in turn causes precession of thegyroscope about its vertical axis 5, whereby the gyroscope returns toits original position.

To compensate the effect of drift of the craft the following means arecombined with the above described and per se well known course goveminginstrument. 3; is a receiving antenna, or rather loop, as generally usedfor determining the direction of a radio sending arrangement provided atthe station which is to be reached by the craft. The receiving loopantenna 63 is electrlcally connected to a receiving and an amplifiercircuit well known in the art and therefore indicated only generally at64. The output side of the lastmentioned circuit 64 is connected to anelectromotor 6'. The axis of the electromotor 6C is mechanically coupledat its one end by means of a difl'erential gear 61 to the spindle 29 andat its other end by means of a differential gear It to the carrier ofthe receiving loop G3, which carrier is mounted for turning about avertical axis. In consequence of the provision of the differential gear68 it is possible to adjust the loop I about a vertical axis by means ofthe motor 66 as well as by hand by means of. an indicator is coupled tothe one side wheel of the diflerential gear II. II is a measuringinstrument connected also to thevoutput of the receiving circuit 64, andII is a regulating resistor.

The arrangement shown operates as follows? At the beginning the loopantenna 6} is adjusted according to the desired course in like manner asthe magnetic compass It and the casing 1 of the gyroscope and thereforeat beginning the loop will be set at an angle of 90 with respect to theradio beam of the station which is to be reached by the craft. Assumingnow that at .any time the craft drifts on account of a lateral wind,then i the craft will laterally be drifted out of the original courseline as, for example, it is shown in Fig. 2. In this figure and also inFigures-3 and 4, B designates the station from which the craft is comingand Z the station toward which the craft is flying. In consequence of Ithe drift, .in position shown in Fig. 2 the radiov beam will enclosewith the loop antenna an angle on. In consequence of this the output ofthe receiving circuit M supplies the motor .6 with current of a certaindirection in a manner known per se,

which motor thereupon begins to run. Thereby on the one hand the coursepredetermined by the adjustment of compass l6 and of the casing 1 willradio beam radiated from the station Z. In condii iii)

sequence of this the motor 66 will cease to run. If the described changeof the course is now right with respect to the drifting of the craft,the latter will attain the station Z on the line .B-Z, that is on theshortest way. In. the other case after some time the craft will attainfor example a point B", as is illustrated in Fig. 4. In this positionthe loop antenna 63 is again deflected from its zero position withrespect to the radio beam. The angle of deflection may be, for example,:2. But'it may be noted that the sense of deflection of. the loopantenna 63 in this case is opposite to the sense of deflection in thecase illustrated in Fig. 2. Therefore the motor t6 begins to run andadjust the loop antenna 63 and the other above mentioned elements in adirection opposite to the direction of rotation in the case shown inFig. 2. From the above description will be seen that after some time thecraft has automatically taken a course which compensates the drifting ofthe craft in such a manner that it will attain the station Z along theshortest path.

it is clear that the radio receiving apparatus used for the abovementioned purposes may be varied in any manner known in the art. Forexample two loop antennae enclosing an angle of lit!" with anotheror anormal and a loop antenna may be used in combination with any adaptedreceiving apparatus, comprising amplifier and rectifier. In each casethe radio receiving arrangement must be such a one that the polarity orcharacteristic of the output will depend on the direction in which thereceiving antenna is deflected from its normal position with respect tothe radio beam.

While I have described my invention as embodied in one form,it should beunderstood that I do not limit my invention thereto, since variousmodifications thereoi will suggest themselves to those skilled in theart without departing from the spirit of my inventiomthe scope of whichis set forth in the annexed claims.

i claim as my invention:

1. In a system for the automatic steering of dirigible craft, thecombination of an absolute direction indicator-including a memberconnected with the craft and a movable member, a steering device, anoperative connection between said movable member and said steeringdevice, an instrument measuring the drift of the craft and means wherebythe said instrument will automatically shift relatively to the craft.that member oi said direction indicator which is connected with theycraft, in such a manner as to compendate for the drift.

2. In a system ,for the automatic steering of dirigible craft, thecombination of an absolute direction indicator including a memberconnected with the craft and a movable member, a steering device, anoperative connection between said movable member and said steeringdevice, a radio direction finder, and means for automatically pointingsaid direction finder toward the destination of the craft andsimultaneously automatically shifting that member of said directionindicator which is connected with, the craft, relatively to said craftin such a manner that the craft'will travel to its destination along asubstantially straight path.

3. In a system for the automatic steering of dirigible craft, thecombination of an absolute direction indicator including a memberconnected with the craft and a movable member, a steering device, anoperative connection between said movable member and said steeringdevice, an instrument measuring the drift of the craft, means wherebysaid instrument will automatically shift relatively to the craft, thatmember of said direction indicator which is connected with the craft,

and means for manually shifting said member relatively to the craftindependently of the automatic steering.

4. In a system for the automatic steering of aircraft, an absolute.direction indicator, electrolytic means for deriving a steeringcomponent from the movement of said indicator, a turn indicator, meansfor deriving another steering component from the movement of said turnindicator; a steering motor, means for causing said motorto be actedupon by both of said components, an instrument measuring the drift ofthe aircraft, and means for shifting automatically the casing of saiddirection indicator relatively-to the said craft, in accordance with theindications of said instrument.

5. In a system for the automatic steering of dirigible craft, thecombination of an absolute direction indicator comprising an azimuthgyroscope and-a compass each of which includes a member connected withthe craft and a movable member, means for shifting the bearings of saidgyroscope in accordance with the indications of said compass, means formanually shifting the position of the casing of said compass, a steeringdevice, an operative connection between said movable members and saidsteering device, an instrument'measuring the drift of the craft, andmeans whereby the said instrument will automatically shift relatively tothe craft, those members of said gyroscope and said compass which areconnected with the craft, in such a manner as to compensate for thedrift.

6. In a system for the automatic steering of diriglble craft, thecombination of an absolute direction indicator comprising an azimuthgyroscope and a compass each of which includes a member connected withthe craft and a movable member, means for shifting the bearings of saidgyroscope in accordance with the indications of said compass, a steeringdevice, an operative connection between said, movable members and saidsteering device, an instrument measuring the drift of the craft, andmeans whereby the said instrument will automatically shift relatively tothe craft, those members of said gyroscope and said compass which areconnected with the craft, in such a manner as to compensate for thedrift.

' '7. In a system for the automatic steering of dirigible craft, thecombination of an absolute direction indicator comprising an azimuthgyroscope and a compass each of which includes a member connected withthe craft and a movable member, means ior shifting the bearings of saidgyroscope in accordance with the indications oi. said compass, means formanually shiiting the position of the casing of said compass, a steeringdevice, an operative connection between said movable members and saidsteering device, an instrument measuring the drift of the craft, andmeans whereby the said instrument will automatically shift relatively tothe craft, that member of said gyroscope which is connected with thecraft, in such a manner as to compensate for the drift.

8. In a system for the automatic steering of dirigible craft, thecombination of a steering device, an absolute direction indicatorincluding a member connected with the craft and a movable member, aconnection by which said steering device is operated from said movablemember, an instrument measuring the drift of the craft, and aconnectionby which the other member of said direction indicator isoperated automatically from said instrument to shift said other memberrelatively to the craft in such a manner as to compensate for the drift.

9. In a system for the automatic steering of dirigible craft, thecombination of a steering device, an instrument measuring the drift ofthe craft, and an indirect connection from said instrument to saidsteering device, said connection including an absolute directionindicator having two members, one of said members being movable andoperatively connected with the steering degym, and means responsive tosaid combined effects for steering the craft.

GERHARD RIEPER.

